Standardization is a critical step. It verifies that we use open IP which is available to everyone, provides a open forum for discussion, and archives the protocol in a way all vendors can use to resolve disputes about how we communicate.
The biggest difference between SPDY and Microsoft's proposal is that Microsoft's proposal is only theory at this point. The SPDY proposal has dozens of independent implementations behind it and 3 years of operational experience.
I'm not trying to dis the proposal; just point out that it is in its infancy. To jump start it, Microsoft started with SPDY at its core, but changed the syntax.
Changing the transport requires patching the kernels of billions of installed devices. SCTP is not available on Windows, Mac, or any popular mobile device I know of.
If you want 100% support; just wait for the IETF to finish HTTP/2.0. It may not be the exact SPDY protocol, but it will most likely support a reasonable form of multiplexing, and I am confident all major browsers will implement it. But its probably ~2yrs away.
We removed the alternate-protocol stuff only because we thought it needed more work. It is implemented in chrome, so you can try it, but we're still considering how we'll deal with it going forward.
Sorry to surprise you, Maciej. As others on this thread have already have already surmised, we were not trying to change (or fork) SunSpider. We just wanted to demonstrate the impact of the smallest possible change when we make it a longer test.
We need HTTP/3.0 to be SSL all the time and nix the CAs so we can avoid MITM from VZ.